A lift lock is a type of waterway structure used to raise and lower boats between different water levels. It consists of a chamber that fills or empties with water, allowing vessels to move up or down a slope. Lift locks are commonly found on canals and rivers where natural elevation changes make navigation difficult. The mechanism of a lift lock typically involves gates at both ends of the chamber. When a boat enters, the gates close, and water is either added or removed to adjust the water level. This process enables safe passage for boats, making waterways more accessible and efficient for transportation.